The present invention relates to a simulation method for a programmable controller (PC), more particularly, the present invention is directed to a simulation method for a PC which performs a logical process on a signal from a screen displaying a ladder program and a signal from a machine, and uses the result as an input signal.
A PC (programmable controller) must be connected to a machine to confirm a created ladder program, etc. If the ladder program is incomplete the machine operation is not complete, and thus only a part of the program can be simulated.
Desirably, simulators are connected to simulate a part of a program that cannot be simulated using the machine. This means that simulators should be prepared at all times, and if a large number of ladder programs are involved, it is difficult to always provide such simulators. Accordingly, a method has been employed in which the input/output is controlled by a keyboard, etc., of a program editing apparatus, to simulate the ladder program.
In the prior art method, however, since the input/output is controlled by using alphabetic or numerical keys of the keyboard, it is difficult to intuitively grasp the relationship with the ladder program, and accordingly, much time is required and setting errors frequently occur.
Further, a satisfactory simulation cannot be achieved if a simulation using a machine and a simulation using the program editing apparatus are carried out separately.